The present invention relates to a finned package, namely one with a sealed wrapper having a longitudinal fin or closure flap, provided with a tear-strip easy-opening device.
It is known that in many sectors of the food industry, especially that of sweets and pasta, wide use is made, for distribution of the products, of packages in which the food product, in relatively rigid boxes or trays of plastics or card material, is further enclosed, together with the rigid container, in a sealed wrapper, generally made with sheets of various materials (paper, aluminium, plastics) connected together.
The Function of the wrapper is to protect the food product from ultra-violet and visible radiation, pollution by external agents, water, bacteria, fungi and insects.
One type of wrapper particularly used is that known as a "flow-pack" in which a flat rectangular sheet is first folded back on itself in such a way as to bring together two opposite edges, which are welded together so as to form a kind of tube in which the product to be protected is housed, and which is then subsequently sealed at its two free ends.
The various welding operations on the edges are in general effected by simultaneous heat and pressure.
This type of wrapper is characterised by a longitudinal fin constituted by the juxtaposition of the two edges of the material of the wrapper which are welded together, and by two tranverse flaps sealing the package.
The opening of this type of package without cutting instruments (scissors, knives) is particularly difficult due to the toughness of the material used for the wrapper and involves the risk of damage to the products contained therein.
It is desirable to provide this type of package with easy-opening devices using tear strips of the type such as those used for other types of packages and for other types of products, such as cigarettes, chewing gum etc, in which a thin plastics film of wrapper is cut by a thread or strip disposed inside the wrapper entirely around an inner container or the product itself so as to form a loop with its ends superimposed but not welded; tearing one end opens the loop thereby separating the whole of the outer wrapper into two separate parts.
Unfortunately it has not until now been possible to obtain the combination of the two characteristics, namely flow-pack with longitudinal fin and tear strip in a single package and achieve the overall desired result.
In fact, attempts to combine the two characteristics give rise to packages in which the tear strip possibly succeeds in tearing and cutting the wrapper where it is not superimposed at its edges, but not at the flaps, and particularly at the longitudinal fin, where the wrapper becomes, because of the sealing, particularly tough, relatively rigid and sharply folded outwardly with respect to the shape of the other surfaces of the wrapper which take up the shape of the inner container or product and are therefore flat or at most convex.
At the flap the tear strip, rather than tearing through the flap, becomes separated from the flap without achieving the desired effect of separating the wrapper into two separate parts to allow easy removal of the contents.